(Ruby) Load Certificate from Smart Card by Key Usage

See more Certificates Examples

You may have a smartcard or USB token that contains only 2 certificates, one for signing, and one for authentication, and you wish to load the certificate for signing. This example demonstrates how to load the 1st certificate found on a smartcard that matches the intended key usage.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

cert = Chilkat::CkCert.new()

# If you know the smart card PIN, set it prior to loading from the smartcard/USB token.
cert.put_SmartCardPin("12345678")

# To load a certificate matching an intended key usage, specify the type of usage as shown below.
# 
# The possible key usage keywords are:
# 
# digitalsignature
# Use when the public key is used with a digital signature mechanism to support security services other than non-repudiation, certificate signing, or CRL signing. 
# A digital signature is often used for entity authentication and data origin authentication with integrity.

# nonrepudiation
# When a digital certificate's key usage includes "nonrepudiation," it implies that the certificate and its associated private key can be used to 
# create digital signatures that provide proof of the origin and integrity of the signed data, and the signer cannot later deny having signed the data.

# Other less common usages:

# certificatesigning
# keyencipherment
# dataencipherment
# crlsigning
# secureemail
# serverauthentication
# clientauthentication
# codesigning
# timestamping

success = cert.LoadFromSmartcard("keyusage=nonrepudiation")
if (success == false)
    print cert.lastErrorText() + "\n";
    print "Certificate not loaded." + "\n";
    exit
end

print "Found: " + cert.subjectDN() + " serial=" + cert.serialNumber() + "\n";